Role of lymphoid DCs in HSV-1 latency

描述(申请人提供)：感染HSV-1的一个标志是感染者的神经节建立潜伏期。在潜伏感染者的一生中，病毒偶尔会重新激活，传播回眼睛，并导致反复发作的疾病。事实上，角膜瘢痕形成(CS)的一个主要原因也被称为疱疹间质角膜炎(HSK)是由HSV-1在潜伏期重新激活后引起的疤痕。减少潜伏期以及随后的反复感染和视力丧失的最有效方法是减少感染小鼠三叉神经节的潜伏期。我们已经证明，在免疫小鼠中，通过耗尽树突状细胞可以显著减少HSV-1的复发感染。潜伏期和复发率的增加与CD11c+CD8+DC有关。我们以前的研究支持这一概念，即将DC群体从CD11c+CD8？+转移到CD11c+CD8？-DC将减少潜伏期的建立和随后在潜伏感染小鼠中的复发。因此，由于与复发性眼部感染相关的问题，预防和/或减少潜伏期的建立应该是针对眼部HSV-1的预防性免疫策略的主要目标。因此，在我们已发表的初步研究的基础上，我们将使用树突状细胞刺激因子来改变树突状细胞的数量，以减少T细胞的耗竭，从而减少眼部感染小鼠TGS潜伏期的建立/维持。我们建议：目的：验证一种假设，即通过减少感染小鼠三叉神经节中T细胞的耗竭，将DC推向髓系相关(CD11c+CD8？-)而远离淋系相关(CD11c+CD8？+)，从而缩短感染小鼠的潜伏期。我们已发表的研究表明，CD11c+CD8？+DC参与了眼部感染小鼠TGS潜伏期的延长。此外，我们的初步研究表明，CD11c+CD8+DC参与了T细胞的耗竭，这种T细胞耗竭与潜伏期的增加有关。我们将测试：(A)聚乙二醇化GM-CSF与GD联合应用是否会通过减少T细胞耗竭而增强免疫小鼠的髓系相关DC，并通过减少T细胞耗竭而进一步缩短免疫小鼠的潜伏期；以及(B)与聚乙二醇化GM-CSF类似，光敏蛋白受体(LT？r)与激动剂Ab激活将推动CD11c+CD8？的扩张，并缩短潜伏期和减少潜伏期，减少潜伏感染小鼠的T细胞耗竭。这些研究的结果将确定通过使用免疫刺激剂进一步刺激CD11c+CD8？-DC以提高针对HSV-1潜伏的DNA免疫效果的重要性。这些疫苗策略的长期效果也将被表征，以确定是否会引发长寿的CD8+T细胞反应。

DESCRIPTION (provided by applicant): A hallmark of infection with HSV-1 is establishment of latency in ganglia of the infected individual. During the life of the latently infected individual,the virus can occasionally reactivate, travel back to the eye and cause recurrent disease. Indeed, a major cause of corneal scarring (CS) also know as herpes stromal keratitis (HSK) is the scarring induced by HSV-1 following reactivation from latency. The most efficient way to decrease latency and thus subsequent recurrent infections and loss of vision is to reduce latency in trigeminal ganglia of infected mice. We have shown that recurrent HSV-1 infection was reduced significantly by depletion of DCs in immunized mice. The increase of latency and recurrences was associated with CD11c+CD8¿+ DCs. Our previous studies support the concept that shifting the DCs population from CD11c+CD8¿+ to CD11c+CD8¿- DCs will reduce establishment of latency and the subsequent recurrences in latently infected mice. Consequently, because of the problems associated with recurrent ocular infection, preventing and/or reducing establishment of latency should be a major goal of a prophylactic immunization strategy against ocular HSV-1. Thus, based on our published and Preliminary Studies, we will use DCs stimulatory factors to shift the DCs population in order to reduce T cell exhaustion and consequently, the establishment/maintenance of latency in the TGs of ocularly infected mice. We propose to: Aim: Test the hypothesis that pushing DCs toward myeloid-related (CD11c+CD8¿-) and away from lymphoid-related (CD11c+CD8¿+) will reduce latency in infected mice by decreasing T cell exhaustion in trigeminal ganglia of infected mice. Our published studies have shown that CD11c+CD8¿+ DCs are involved in the enhancement of latency in the TGs of ocularly infected mice. In addition, our preliminary studies suggest that CD11c+CD8¿+ DCs are involved in exhaustion of T cells and this T cell exhaustion is involved in the increase of latency. We will test whether: (a) Co-administration of pegylated GM-CSF with gD will enhance myeloid-related DCs and further reduce latency in immunized mice compared with mice that treated with GM- CSF and gD by reducing T cell exhaustion; and (b) Similar to pegylated-GM-CSF, activation of the lymphotoxin ¿ receptor (LT¿r) with an agonist Ab will drive the expansion of CD11c+CD8¿- and reduce latency and decrease T cell exhaustion in TGs of latently infected mice. The results of these studies will determine the importance of further stimulating CD11c+CD8¿- DCs through the use of an immune stimulator to improve the efficacy of DNA immunization against HSV-1 latency. The long-term effects of these vaccine strategies will also be characterized to determine whether long-lived CD8+ T cell responses are elicited.